JP2826864B2 - Method and apparatus for rapid melting tapping by supplying cold material to aluminum ingot - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for rapid melting and tapping of aluminum or aluminum alloy (hereinafter abbreviated as aluminum-based metal) ingots, and more specifically to aluminum-based metals. When casting the molten metal as a member of a machine or electrical equipment by die casting or the like, an aluminum-based metal ingot (aluminum ingot) 1-2 just before a pouring slot of a die of a die casting machine or a pouring port of other casting equipment. The individual pieces are melted directly by induction heating, so-called cold material insertion melting method, melted down to a temperature rising area to form a molten metal, and the heated molten metal is conveyed upward by an electromagnetic pump and is transferred to a die of a die casting machine. TECHNICAL FIELD The present invention relates to a method and an apparatus for rapidly dissolving molten metal in a molten metal.

[Prior art] As structural members for general machinery, special machinery, vehicles, electric equipment, etc., aluminum has the characteristics of low specific gravity and low melting point, and if it is an alloy, it should have considerable strength. It is widely used as a wrought material or a cast product because it can be made.

Die casting, shell mold casting, centrifugal casting, etc. are used in addition to ordinary mold and sand casting as castings. Among them, the die casting method uses a die casting machine (also called a die casting machine), Can be repeatedly injected at a high pressure and at a high speed into a die mold called a die, so that a precision cast product can be obtained. Therefore, it is increasingly used to meet the requirements of dimensional accuracy and productivity.

However, in general, in order to supply molten metal to a die casting machine, as shown in FIG. 3, a large amount of intensive melting is performed by a melting furnace 31 using gas or heavy oil as a heat source, and the molten metal is heated to 570 to 600 ° C. Transfer to a holding furnace 32 that uses heavy oil as a heat source, hold it for a long time, and then transfer it to a hand furnace 34 by a transportation means such as a trolley 33, raise the temperature to approximately 720 ° C, which is suitable for pouring, and use human power or a robot. The method of supplying the material into the die slot 37 of the die casting machine 36 by 35 or the like is followed.

[Problems to be Solved by the Invention] However, such a method requires a large factory space because of a large-scale operation process using many furnaces, and requires a long time using a plurality of furnaces. In order to maintain the material in the molten state and transport it between multiple furnaces, in addition to the disadvantage of low material yield due to loss such as burning, oxidation and scattering of the material, there is a lot of energy loss due to exhaust heat and heat radiation. It was uneconomical in terms of terms.

In addition, there are many processes such as transport, storage, and pumping of the molten metal, and the work efficiency is low. In addition, there is a concern about safety and there are drawbacks in terms of working conditions.

Furthermore, since the rise time until the temperature of the large-capacity furnace is raised to a predetermined temperature is long, there is a problem concerning working conditions such as the need for a melting worker to go to work early, and a solution has been demanded.

The inventor of the present invention solves the above-mentioned problem with the molten metal supply device using a large-capacity melting furnace, an intermediate holding furnace, a hand-held furnace, and the like, by using an aluminum ingot for a die of a die casting machine and other casting machines. Dissolve directly just before the pouring port,
Although the concept of adopting a cold material rapid melting method in which the temperature is raised to a predetermined pouring temperature and then poured into a die was solidified, it was necessary to solve the following points.

Heat source of heating energy and melting chamber structure for cold material insertion melting of aluminum ingot.

Structure of cold material supply device for inserting aluminum ingot into melting chamber.

The structure of the heating means and the heating chamber for containing the molten aluminum and raising the temperature to a predetermined pouring temperature.

A method of pouring from the melting chamber to the heating chamber and from the heating chamber to the pouring slot for die casting.

Ancillary equipment related to the above.

[Means for Solving the Problems] In the present invention, the number of furnace bodies, induction heating coils, electromagnetic pumps, and the like are minimized in solving the above-mentioned problems relating to the insertion, melting, and pouring of cold material. The most important goal was to adopt the following method and apparatus for rapid melting and tapping of aluminum ingots.

First, the rapid melting tapping device will be specifically described. This device is composed of the following parts.

(A) The upper end has an opening serving as an insertion opening for an ingot of an aluminum-based metal, and the lower end has an opening serving as a base of an outlet through which a heated molten metal flows radially outward. Melting, as a metallurgical vessel for raising the temperature, an inner furnace body for melting and raising the temperature, and inserting the inside of the inner furnace into a position near the lower end of the inner furnace body, dividing the inner furnace into a melting chamber and a heating chamber, and An upright hollow cylindrical inner furnace having a mushroom-shaped current plate that allows the molten metal that has been melted in the insertion / melting chamber to pass through and flow down.

(B) an outer furnace which is coaxially arranged outside the inner furnace and has an inner diameter enough to form an annular space sufficient for the molten metal to pass and flow between the inner furnace and the upper furnace; An upright hollow cylindrical outer furnace having a molten metal discharge port communicating with the defined annular gap between the upper end of the inner furnace and an opening at a lower end for discharging extra residual hot water, slag, and the like. .

(C) The remaining part of which is partially inserted into the opening at the lower end of the inner furnace projects toward the opening at the lower end of the outer furnace and closes the opening at the lower end of the outer furnace. A block having at least one molten metal passage for shutting off the space between the lower end and the opening, but for communicating the inside of the inner furnace with the annular space.

(D) an induction heating coil arranged on the outer periphery of the outer furnace to melt a cold material of the aluminum ingot in the insertion / melting chamber and to raise the temperature of the molten metal in the heating chamber to a predetermined pouring temperature.

(E) a thrust force is applied to the molten metal that is disposed below the induction heating coil on the outer periphery of the outer furnace and is stored in the heating chamber and the annular space communicating therewith and heated to a predetermined pouring temperature. And an electromagnetic pump for flowing upward in the annular gap and pouring the molten metal out of the furnace from the tap hole.

The inner furnace and the outer furnace each have a flange extending radially outward at an upper end thereof, and the flange of the inner furnace is disposed at a position higher than the flange of the outer furnace,
It is preferable that an annular tapping path is formed between the upper and lower flanges and communicates with the annular gap and communicates with the tapping hole.

It is convenient if the inner furnace is composed of two parts, upper and lower parts, which are integrally connected by a solder joint.

Also, the block is preferably connected to the lower end of the inner furnace via a metal ring such as cast iron.

Next, the rapid melting tapping method of the present invention will be described below.

(A) An aluminum ingot is inserted as a cold material into a melting chamber of an inner furnace for insertion and melting, and melting proceeds while forming droplets from the surface toward the inside.

(B) The formed droplets are caused to flow down into the temperature raising chamber, and are further flowed into an annular space defined between the inner furnace and the outer furnace and communicated with the lower end of the inner furnace to form a molten metal pool.

(C) The temperature is raised by induction heating using a melting and temperature raising coil. If the aluminum ingot being melted decreases to a predetermined length or less by melting during that time, the next aluminum ingot is inserted and replenished.

(D) When the temperature of the molten metal in the molten pool reaches a predetermined temperature, the electromagnetic pump is energized, and the molten metal in the heating chamber and the annular space is conveyed upward through the annular space and discharged from the tap hole.

The aluminum ingot inserted into the melting chamber was 2
It is convenient to insert the individual pieces into a set with their flat bottoms in contact with each other and back to back.

[Operation] The inner furnace and the outer furnace have a double-pipe structure, and the two are connected by a molten metal passage opened in the lower part of the block. However, there is an opening through which the molten metal flows out naturally by gravity. Therefore, the molten metal can be held in the furnace without operating the electromagnetic pump during the temperature rise.

While the molten metal is stored in a state communicating with the heating chamber of the inner furnace and the annular gap between the inner furnace and the outer furnace, a predetermined amount of magnetic flux is generated by a magnetic flux from an induction coil for melting and raising the temperature which interlinks with the molten metal. The temperature is raised to the tapping temperature.

The hollow straight tubular melting and heating inner furnace can be set in the outer furnace as a cassette type inner furnace in advance, and can be removed. It is manufactured separately in two parts of the bath room, joined by a lanyard joint and, in the event of damage, each is made separately replaceable.

The thus-coupled inner furnace body has an outer flange, the inside of which has an insertion / melting chamber from the top serving as an insertion port of the aluminum ingot to the middle straightening plate and the lower end serving as an outlet of the molten metal from the straightening plate. It is composed of two parts, a heating chamber.

Embodiment FIG. 1 is a side sectional view showing a preferred embodiment of the rapid melting and tapping apparatus of the present invention.

In FIG. 1, 1 indicates the entire rapid melting and tapping apparatus,
Reference numeral 2 denotes a melting, heating, and pouring furnace (inner furnace) main body, and 3 denotes an outer furnace for inserting and setting the inner furnace main body 2 to define an annular gap 4 for heating and pouring. Yes, the whole apparatus has a hollow straight cylindrical double pipe structure.

The outer furnace 3 is arranged as an upright cylindrical tube with a bottom capable of accommodating the inner furnace 2 with a sufficient annular space 4 inside, and has an outwardly protruding flange 9 on an upper opening surface and a bottom center. A discharge hole 5 is provided.

When setting the cassette type,
Ring 7 made of cast iron or the like attached to the lower end of
When the straight cylindrical block 6 made of a refractory material is fitted inside the lower furnace 3 so as to be seated in the upper opening tapered opening through the through hole, the centering is made centered.

The straight cylinder block 6 is provided with a molten metal passage 11 communicating with the annular space 4 diagonally downward from the upper surface toward the side surface.

When the inner furnace 2 is set in the outer furnace 3, the annular gap 4 formed between the outer wall of the inner furnace 2 and the inner wall of the outer furnace 3 is used as a tapping passage when the molten metal rises backward. .

The inner furnace 2 has a relatively long hollow cylindrical insertion / melting chamber 14 from an upper open end 12 having a flange 8 projecting radially outward and serving as an insertion port for an aluminum ingot as a cooling material, to a straightening plate 15. And a temperature-raising chamber 17 from the current plate 15 to a lower end portion 16 below which serves as a discharge port for remaining hot water and slag,
It is composed of three parts, namely a metal ring 7 and a sealed column part composed of a cylindrical block 6.

At the outer periphery of the outer furnace 3, from the insertion / melting chamber 14 of the inner furnace 2 to the heating chamber
An electromagnetic pump for injecting the melting / heating coil 18 into a portion corresponding to the area up to the upper part of the furnace 17, and injecting the molten metal to the outer periphery of the outer furnace 3 corresponding to the area below the coil to the lower end of the outer furnace 3. 19
Are arranged respectively.

The heating chamber 17 of the inner furnace 2 and the portion of the annular gap 4 communicating therewith serve as a molten metal pool, as well as a heating and pouring area having a pouring port, and the insertion / melting chamber 14 serves as a part for inserting and melting an aluminum ingot. This is the insertion / dissolution zone that also serves as a temperature rise.

The heating / pouring area and the insertion / melting area are separated by a slat-shaped rectifying plate 15 which is arranged in the middle between the two and has a large number of slots.

This rectifying plate 15 prevents the aluminum ingot inserted from the upper open end 12 from dropping to the heating chamber 17 due to gravity, restrains the aluminum ingot in the insertion / melting chamber 14, and performs induction heating. Aluminum droplets that melt from the surface of the aluminum ingot and fall while raising the temperature pass through the slots and flow into the temperature raising chamber 17 to form and hold a molten metal pool.

 Next, the operation method of the above embodiment will be described.

The normal operation steps of heating and pouring are repeated in a state where the two hollow straight pipe portions of the outer furnace and the inner furnace are both arranged upright.

(1) The aluminum ingot is non-standard and its shape and dimensions are not specified, but usually, as shown in FIG. 2 (A), the bottom surface 21 is almost flat and the top surface 22 has a V or U-shaped groove 23. There are formed two or three trapezoidal projections 24 partitioned by. Then, as shown in FIG. 2 (B), two aluminum ingots
20 flat bottoms 21 are back-to-back to form a pair, and a unit for transportation and melting. U-shaped grooves 23 on a surface 22 on both right and left sides are engaged with claws of a gripping member of a cold material supply device (not shown). Utilizing the groove to be combined, it is transported to the upper open end 12 shown in FIG.

(2) The melting / heating coil 18 is energized to melt the aluminum ingot in the insertion / melting chamber 14 from its surface as droplets by induction heating. The droplets thus formed are located on the lower current plate.
After passing through 15, it is dropped into the temperature raising chamber 17, passes through the molten metal passage 11, flows into the annular space 4, forms and holds a molten metal pool,
In the meantime, the temperature is raised to a predetermined pouring temperature by induction heating by the melting / heating coil 18.

(3) When the temperature of the molten metal reaches a predetermined temperature, the electromagnetic pump 19 is energized to raise the molten metal from the bottom of the annular space 4 to a level beyond the flange 9 of the outer furnace 3 against gravity. Thus, the molten metal in the heating chamber 17 passes through the molten metal passage 11 and is injected radially outward, hits the bottom of the inner wall of the outer furnace 3, and the flow direction is changed upward, and together with the molten metal in the annular space 4. It rises to a height exceeding the flange 9 of the outer furnace 3 and is poured into the die slot of the die casting machine.

(4) When discharging unnecessary remaining hot water or slag, or when repairing the inner walls of the inner furnace 2 and the outer furnace 3, etc., the cassette type inner furnace 2 is taken out of the outer furnace 3 and discharged. The block 6 made of a refractory material that closes the outlet 5 is removed and dropped from the block 5 to a noro receiving place, a repair yard, or the like, and discharged.

(5) When replacing the entire inner furnace 2, the damaged inner furnace 2 is taken out of the outer furnace 3, repaired or discarded, and another inner furnace is inserted into the outer furnace 3.

If the inner furnace 2 is composed of two parts, upper and lower parts, and they are connected by a solder joint, they can be individually separated and replaced.

[Effects] As can be understood from the above description, in performing the so-called cold material insertion melting in which an aluminum ingot is inserted and melted immediately before the die slot of the die casting machine, according to the apparatus of the present invention, the structure and operation Many advantages are achieved in terms of:

(B) As a furnace for melting and raising the temperature of an aluminum ingot, a melting chamber and a temperature raising chamber adopt an upright bored inner furnace in which the melting chamber and the heating chamber are continuously connected with a veneer-shaped current plate interposed therebetween. Inserting an aluminum ingot as a cooling material, melting sequentially from the surface of the aluminum ingot in the melting area, flowing down as a large number of droplets to the temperature rising area, raising the temperature until the pouring temperature is reached, melting and raising the temperature of the aluminum ingot Is shared by a single induction coil. Since melting and heating can be performed by a single inner furnace and a single induction heating coil, the structure is simple and the production cost can be reduced.

(B) An annular gap between the outer furnace and the inner furnace is used as a passage for discharging the heated molten metal, and the flow of the molten metal is reversed upward by an electromagnetic pump. Can be reduced, and can be installed in a relatively low factory building.

(C) The inner furnace for melting and heating can be attached to and detached from the outer furnace in the form of a cassette, and the inner furnace itself can be separated into two parts, upper and lower, so that they can be connected to each other. Keep it,
They can be repaired or replaced.

(D) When raising the temperature of the molten metal, there is no need to hold the molten metal in a temperature-raising area or the like against the gravity by an electromagnetic pump, so there is no fear of the molten metal being ejected during a power failure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 (A) is a perspective view showing a typical shape of an aluminum ingot, and FIG. FIG. 3 is a side view showing a state where two aluminum ingots are paired, and FIG. 3 is a schematic process diagram showing a conventional melting and pouring method. References in the drawings: 1: rapid melting and tapping equipment, 2: inner furnace, 3: outer furnace, 4: annular gap, 5: outlet, 6: block, 7: metal ring, 8, 9: flange, 11: molten metal Passageway, 12: Upper open end, 14: Insertion / melting chamber, 15: Rectifier plate, 16: Inner furnace lower end, 17: Heating chamber, 18: Melting / heating coil, 19: Electromagnetic pump, 20: Aluminum ingot, 21: Flat bottom.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F27B 1/10 F27B 1/10 (56) References JP-A-1-165727 (JP, A) (58) Fields investigated (Int. .Cl. ⁶ , DB name) F27B 1 / 04,1 / 10 C22B 9/16 B22D 37 / 00,45 / 00

Claims (6)

(57) [Claims] When a molten metal of an aluminum-based metal containing aluminum and its alloy is poured into a casting machine such as a die casting machine, an aluminum ingot of a component corresponding to the molten metal is used as a cooling material at a position close to the casting machine. This is a rapid melting and tapping device that uses an aluminum ingot to supply, melts, and raises the temperature of the molten metal by rapid melting. The opening at the upper end serves as an insertion port for an aluminum-based metal ingot, and the temperature rises at the lower end. An opening serving as a base of an outlet for allowing the melt to flow outward in the radial direction has an opening serving as a base for an aluminum ingot, melting of a cold material, melting as a metallurgical vessel for raising the temperature, an inner furnace body for raising the temperature, and At the position near the lower end of the inner furnace main body, the inside of this inner furnace is divided into an insertion / melting chamber and a heating chamber, and a slender shape that allows the molten metal melted in the insertion / melting chamber to flow down. An inner furnace having an upright hollow cylindrical shape having a straightening plate, and a coaxially disposed outside of the inner furnace, and only forming a tubular gap between the inner furnace and the inner furnace, which is sufficient for the molten metal to pass and flow. A furnace outlet having an inside diameter defined between the upper end of the furnace body and the upper end of the inner furnace, the outlet of the molten metal communicating with the defined annular gap is defined, and the lower end discharges extra residual hot water, slag, etc. An outer furnace of an upright hollow cylindrical shape having an opening for carrying out, a part is inserted into the opening at the lower end of the inner furnace, and the rest projects toward the opening at the lower end of the outer furnace to close the opening at the lower end of the outer furnace. Usually, a block having at least one molten metal passage for communicating between the inside of the inner furnace and the annular space, which blocks the inside of the inner furnace and the opening of the lower end of the outer furnace, To dissolve the cold material of the aluminum ingot inside the insertion and melting chamber An induction heating coil for raising the temperature of the molten metal in the heating chamber to a predetermined pouring temperature, and an annular gap disposed below the induction heating coil on the outer periphery of the outer furnace and communicating with the heating chamber and An electromagnetic pump for applying thrust to the molten metal stored therein and heated to a predetermined pouring temperature to cause the molten metal to flow upward in the annular gap and to pour the molten metal out of the furnace from the tap hole. A rapid melting and tapping apparatus for supplying an aluminum ingot with a cold material. 2. An inner furnace and an outer furnace each having a flange extending radially outward at an upper end thereof, wherein the flange of the inner furnace is disposed at a position higher than the flange of the outer furnace. 2. The rapid melting and tapping apparatus according to claim 1, wherein an annular tapping path is formed between the flanges and communicates with the annular gap and communicates with the tapping hole. 3. The rapid melting and tapping apparatus according to claim 1, wherein the inner furnace comprises upper and lower parts and is integrally connected by a soldering joint. 4. A cooling material supply for an aluminum ingot according to claim 1, wherein the block is connected to a lower end of the inner passage via a metal ring made of cast iron or the like. By rapid melting tapping equipment. 5. A rapid melting and tapping method in which a cold material of an aluminum ingot is supplied and melted by rapid melting, and the temperature is increased and the molten material is poured. The cold material is supplied by inserting and melting the aluminum ingot as a cold material. Inserting into the melting chamber of the internal furnace, melting proceeds while forming droplets from the surface toward the inside, and the formed droplets are allowed to flow down to the heating chamber,
Furthermore, the molten metal is formed into an annular gap defined between the inner furnace and the outer furnace and communicated with the lower end of the inner furnace, thereby forming a molten metal pool. If the aluminum ingot being melted is reduced to a predetermined length or less by melting, insert the next aluminum ingot and replenish it, and when the melt in the melt pool reaches a predetermined temperature, energize the electromagnetic pump, and A method for rapid melting and tapping by supplying a cold material to an aluminum ingot, wherein the molten metal in the heating chamber and the annular gap is conveyed upward through the annular gap and discharged from a tap hole. 6. An aluminum ingot to be inserted into the melting chamber,
6. The method according to claim 5, wherein the individual pieces are made into a set, and the flat bottoms thereof are brought into contact with each other and inserted in a back-to-back state.